Otter board for fishing nets



R. DE BOER ET AL OTTER BOARD FOR FISHING NETS Filed Aug. 18, 1924 Patented Aug. 4, 1925.

warren ROELOF DE BOER AND HENRI \VILLEIE DE VOOG-T, OF HEEMSTEDE, NETHERLANDS.

OTTER BOARD FOR FISHING NETS.

Application filed August 18, 1924. Serial No. 732,814.

To all whom 2'2? may concern Be it known that we, Bonror on Bonn and HENRI lViLLEM on Vooc'r, both subjects of the Queen of the l letherlands, residing at Heemstede, the Netherlands, have invented certain new and useful Improvements in and Relating to @tter Boards for Fishing Nets, of which the following is a specification.

The invention relates to otterboards for fishing nets.

The otter-boards are generally used for the purpose of giving the cables or nets, to which they are connected, a certain deviation from the direction in which the boards are trailed.

Frequently they are employed in connection with trawl nets for ground fishing. Though the invention more especially relates to this kind of board, it is not restricted thereto, but otterboards constructed in accordance with the principle of the invention may be used in all those cases in which cables or nets should obtain a direction or spreading, deviating from the towing direction of the board.

The invention consists in an otterboard formed as a flat, preferably oblong, box both of the widest longitudinal walls of which meet each other at the short sides in such a way that a section through these walls in the trailing direction shows a flat inner wall and a convex outer wall with the meeting edges of the walls rounded. 1

By this construction of the board a greater sheering action is obtained than with any other otterboard of the known kind because the experience gained in modern aero-technics is taken into account and only the smallest possible resistance arises during the trailing of the board through the water.

Moreover, the said formation of the board makes it possible to rebuild in a simple way and at low cost existing flat boards.

In employing the board as an otterboard for ground net-s it has the advantage of be ing wide, so it will easily maintain its normal upright position and not catch behind stones on rocky ground nor cut grooves in a weak bottom and increase the resistance.

The invention and its various features will be more fully understood with reference to the accompanying drawings, illustrating an otterboard for ground nets by way of example Figure 1 is a side elevation;

Figure 2 a horizontal section on the line .L.l-ll in -Figure 1, and

Figure 3 a vertical section on tle line lITl in Figure 1. The hoard consists of a flat wooden inner wall 1 and a bent wooden outer wall 2. The latter is constructed in accordance with the tieory of the bearing surfaces of aeroplanes and by this reason a minimum resistance during the towing through the water is obtained with a maximum sheering action.

The walls 1 and 2 are connected atthe front side to a stem post 3 and at the rear side a filling piece 4 is provided. By this construction it may be noted that the flat box formed comprises two relative wide longitudinal walls which meet each other at the ends, namely, at the stem post 3 and the filling 1 so that a horizontal section reveals the fiat inner wall and the convex outer wall with the forward and rearward edges rounded.

At the top the walls are closed by a cover and at the bottom they are connected to a keel 6. This keel of preferably semicircular section is made of cast steel and its outer surface, as far as it extends beyond the walls, is provided with a lining of hard rubber 7.

Between the walls a stiffening frame of angle iron is provided, the longitudinal angle irons 8 being located directly against the walls and the vertical angle irons 9 being connected to filling pieces 10 between the walls.

Moreover, at the outside of the walls ver tical stiffening strips 11 are provided at the place of the filling pieces 10; two diagonals of flat iron 12 against the flat inner wall 1 are provided with holes 13, 14, for

attaching the ground rope and the headline of the net.

The keel 6 is over its whole length provided with a vertical stiffening rib 15 and curved at the front side. The board may be connected to the towing rope by means of the braces 16, 17.

Having now particularly described and ascertained the nature of our said invention and in what manner the same is to be performed, we declare that what we claim is 1. A box-shaped otterboard for ground fishing, a horizontal section of which shows a flat inner wall and a convex outer wall.

2. Improvedetterlaoard to he need in 15 material interconnected with the bottom of trawling and other similar purposes which is formed as a flat box bothlongitudinal walls of which meet each other at the short sides in such a way that a section through these walls in the trailing direction shows a flat inner wall and a convex outer wall, and the meeting edges of the walls being rounded.

3. A boX-shaped otterboard for ground fishing showing in horizontal section a flat longitudinal inner wall and a convexlongitudinal outer wall, said walls being rounded at their meeting edges, a cover interconnecting the walls at the top, a keel of resistant ilzhelwalls, and a stiffening means within said ree 4. A box-shaped otterboard for ground fishing including spaced longitudinal walls, a cover connecting the Walls at the top, a metal stiffening frame arranged inside the cover, a metal keel semicircular in cross section connected at the bottom of the walls and extending throughout the length thereof, and a lining of hard rubber provided about the keel.

In testimony whereof we aflix our signatures.

ROELOF DE BOER. HENRI WILLEM DE VOOGT. 

